This invention relates generally to refrigeration systems and, more particularly, to a noise suppressing jumper tube for connecting a refrigeration condenser and evaporator.
One type of refrigeration system includes, in closed series fluid communication, an evaporator, a compressor, a condenser, a capillary tube, and a jumper tube. The compressor receives a refrigerant from the evaporator and compresses the refrigerant. The compressed refrigerant is supplied to the condenser. Refrigerant flowing out of the condenser enters the capillary tube, which restricts flow of refrigerant from the condenser and maintains a pressure differential between the evaporator and the condenser. The jumper tube connects the capillary tube and the evaporator and provides a transition from the small diameter capillary tube passage and the large diameter passage in the evaporator.
The refrigerant discharged from the capillary tube may be in the form of a liquid, a gas, or a combination of liquid and gas. A portion of the refrigerant vaporizes as it is discharged from the capillary tube into the relatively low pressure environment of the evaporator via the jumper tube. The pressure difference between the refrigerant in the capillary tube and the refrigerant in the evaporator causes liquid refrigerant flowing subsonically through the capillary tube to flow near or above supersonic velocities as it is discharged from the capillary tube and vaporizes. It is believed that the transition between subsonic and supersonic flows and/or the vaporization process, causes a popping noise similar to the sound of a woodpecker pecking on wood (sometimes referred to as woodpecker noise or "WPN") as the refrigerant expands in the jumper tube and in the evaporator.